Field
The disclosure relates to integrated techniques for detecting real power delivered to the load of a transceiver.
Background
Modern radio-frequency (RF) integrated transceivers include circuitry for performing both transmit (TX) and receive (RX) functions on a single chip. The transmit processing circuitry may include, e.g., a TX signal generator, up-conversion mixers, a power amplifier for driving a TX load, etc. The receive processing circuitry may include, e.g., a low-noise amplifier, down-conversion mixers, filters, etc. A baseband processor may be coupled to the transceiver to perform digital operations associated with the TX and RX functionality.
The TX side of the transceiver may often be called upon to drive an off-chip load, such as an antenna for transmitting the TX signal wirelessly. When the load is coupled to the TX circuitry, the impedance of the load may sometimes be indeterminate, or may vary across different samples. For example, the antenna impedance may vary across different antenna samples, and/or the impedance of an interconnect coupling the antenna to a power amplifier of the TX circuitry may be indeterminate. The load impedance may accordingly alter the real power delivered by the transceiver to the load from its nominal value. Such alteration may undesirably result in excess power consumption.
Prior art techniques for addressing this issue include, e.g., using on-chip envelope detectors to estimate the actual power delivered to the off-chip load. However, such envelope detectors do not provide information on the real versus reactive components of the power delivered, as the phase information associated with the delivered power is generally lost during envelope detection. It would be desirable to provide efficient and accurate techniques for determining the real power delivered to a load by a transceiver, that are further readily suitable for on-chip integration with standard transceiver architectures.